The inventors Neal Chaves and David Mendelsohn, each have more than fifteen years of professional photography experience. The third inventor, Philip Doucette, is an electrical engineer skilled in electronic circuit design. Our work has often taken us to remote locations where lighting equipment, primarily electronic flash, is powered from long extension cords, or from generators, inverters, or batteries. In many of these situations, where the light from three or four large electronic flash units would be very desirable, the current capacity of the electrical source permits the use of only one.
Commercial photographers frequently employ the largest and most powerful of these electronic flash "power packs". These units demand high levels of electrical current (in excess of 90 AMPS) in a surge while re-charging after the flash, and then "idle" or "float" at a much lower level (1 to 2 AMPS) until discharged again. Re-cycle time for large units ranges between one and six seconds. A few designs have internal circuits to slow down the re-cycle rate of the individual unit, but still produce significant current surges, and these existing circuits do not achieve or fulfill the purpose of the present invention. The characteristic pattern of power consumption produced by large electronic flash units usually dictates that no more than one such unit may be connected to a single 15 or 20 AMP service main, or blown fuses and tripped circuit breakers will result.
In response to this limitation imposed upon our needs and the needs of other photographers, we conceived and reduced to practice the power management circuit for large electronic flash units which is the basis of the stand-alone accessory device we call THE MAGIC BUS. To the best of our knowledge, based on our years of experience in the fields of photography and lighting, and on our continuing review of all relevant professional journals, no similar device for use with electronic flash systems has been produced or proposed by other inventors.